Mercurial > hg-old > index.cgi
view src/parse.c @ 257:e27279180a73 2.x
Added support for include path to LWASM
author | lost |
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date | Tue, 22 Dec 2009 04:53:20 +0000 |
parents | f59c0916753d |
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/* parse.c Copyright © 2008 William Astle This file is part of LWASM. LWASM is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. */ /* Contains the general parser */ #define __parse_c_seen__ #include <ctype.h> #include <string.h> #include "lwasm.h" #include "instab.h" #include "util.h" // parse a line and despatch to the appropriate handlers for opcodes int lwasm_parse_line(asmstate_t *as, lwasm_line_t *l) { char *p, *p2; char *opc; int opnum; char *sym = NULL; // if this was a bad op first pass (or otherwise a no-process line) // ignore it if (l -> badop) return; p = l -> text; l -> sect = as -> csect; // blank lines are a no brainer if (!*p) { as -> context = lwasm_next_context(as); return 0; } // for output generation later but only on pass 1 // also used by some pseudo ops on pass 2 if (as -> passnum == 1) l -> codeaddr = as -> addr; // if it's a comment, return (this doesn't cause a context change) if (*p == '*' || *p == ';') return; // if we start with a non-space character, it's a symbol if (!isspace(*p)) { // we have a symbol specified here // parse it out and record it for later use for (p2 = p; *p2 && !isspace(*p2); p2++) /* do nothing */ ; sym = lwasm_alloc((p2 - p) + 1); sym[p2 - p] = '\0'; memcpy(sym, p, p2 - p); p = p2; } l -> sym = sym; // now skip any whitespace to find the opcode while (*p && isspace(*p)) p++; // is the line blank? if (!*p && !sym) { // nothing but white space *is* a context break as -> context = lwasm_next_context(as); return; } // parse the opcode for (p2 = p; *p2 && !isspace(*p2); p2++) /* do nothing */ ; opc = lwasm_alloc((p2 - p) + 1); memcpy(opc, p, p2 - p); opc[p2 - p] = '\0'; debug_message(2, "Found operation code: '%s'", opc); // skip intervening whitespace if present while (*p2 && isspace(*p2)) p2++; // look up instruction in insn table for (opnum = 0; instab[opnum].opcode; opnum++) { if (!strcasecmp(instab[opnum].opcode, opc)) break; } // if we found no operation, check if we had a comment // the reason this check is here is to allow for "private" // operation codes like "*pragma" which will be ignored by // other assemblers // also skip empty ops if (!(instab[opnum].opcode)) { if (*opc == '*' || *opc == ';' || !*opc) goto done_line; } // now we have the opcode and the symbol, we can decide if we're // actually going to do anything with this line // we will NOT call the function if any of the following are true: // - we are skipping a condition and the operation code is not a conditional // - we are defining a macro and the operation code is not ENDM // we will call the function in any other circumstance // first condition above if (as -> inmacro && instab[opnum].endm == 0) { add_macro_line(as, l -> text); goto done_line; } // second condition above if (as -> skipcond && instab[opnum].iscond == 0) goto done_line; // we've registered the symbol as needed // now we need to check for a macro call IFF we don't collide with // an operation code; otherwise, call the operation function if (instab[opnum].opcode) { if (instab[opnum].fn) { (instab[opnum].fn)(as, l, &p2, opnum); } else { // carp about unimplemented operation register_error(as, l, 1, "Unimplemented operation code: %s", opc); } } else { if (expand_macro(as, l, &p2, opc) == 0) goto done_line; // carp about an unknown operation code and note that fact for // pass 2 in case a macro appears later with the same name! register_error(as, l, 1, "Uknown operation code: %s", opc); l -> badop = 1; } done_line: if (!(as -> skipcond || as -> inmacro)) { // register symbol if the operation didn't if (sym && instab[opnum].setsym == 0) { if (as -> passnum == 1) { debug_message(1, "Registering symbol '%s' at %04X", sym, l -> codeaddr); if (lwasm_register_symbol(as, l, sym, l -> codeaddr, SYMBOL_NORM) < 0) l -> sym = NULL; else l -> addrset = 1; } } } l -> sect = as -> csect; l -> context = as -> context; lwasm_free(opc); if (sym) lwasm_free(sym); }